This invention relates to improvements in methods of and in apparatus for ascertaining and utilizing certain parameters of plain or filter cigarettes, cigars, cigarillos, filter rod sections and certain other rod-shaped articles. More particularly, the invention relates to improvements in methods of and in apparatus for ascertaining the diameters of rod-shaped articles while the articles move lengthwise, e.g., for ascertaining the diameter of a cigarette rod which is caused to move lengthwise through a monitoring station prior to being subdivided into discrete plain cigarettes of unit length or multiple unit length.
The invention also relates to improvements in methods of and in apparatus for altering or correcting the diameter of a rod-shaped article which is caused to advance lengthwise, which tends (at least a times) to exhibit or develop a diameter which departs from a desired or required or optimum value, and wherein a rod-like filler is surrounded by a tubular envelope or wrapper of cigarette paper, artificial cork or other so-called tipping paper or other web-like wrapping material for plain or filter cigarettes or the like.
The invention further relates to improvements in machines (such as production lines each of which includes a cigarette maker, a maker of or a storage facility for tipping paper, a maker of or a magazine for filter mouthpieces and a maker of filter cigarettes or analogous rod-shaped products of unit length or multiple unit length) wherein the diameter(s) of a running rod-shaped article or of several running rod-shaped articles is or are or can be influenced by signals denoting the ascertained diameters of finished or partly finished rod-shaped articles.
Although the method and the apparatus of the present invention can be put to use for the monitoring of diameters of a wide variety of rod-shaped articles, one of their presently preferred uses is in connection with the mass production of rod-shaped articles which can constitute smokers' products (with or without filter mouthpieces) or which constitute filters for smoke (such as mouthpieces for use in the making of filter cigarettes, filter cigarillos and the like).
An important aspect of the making of high-quality rod-shaped smokers' products (such as filter cigarettes) is to ensure that all components of such articles exhibit diameters which match or at least very closely approach predetermined diameters. For example, a continuous cigarette rod wherein a so-called rod-like filler of natural, artificial and/or reconstituted tobacco is confined in a tubular envelope or wrapper of cigarette paper or the like must or should have a predetermined (optimum) diameter, especially if the rod is to be subdivided into plain cigarettes of unit length or multiple unit length.
If the thus obtained plain cigarettes are to be packed and sold as plain cigarettes, adherence to a predetermined optimum diameter is desirable for the convenience of assembling such plain cigarettes into arrays (e.g., into so-called quincunx formations wherein a median layer of six parallel cigarettes is flanked by two layers of seven parallel cigarettes each, and wherein the cigarettes of the median layer are staggered (offset) relative to cigarettes in the outer layers). Adherence to an optimum diameter is desirable on the additional ground that it enhances the appearance of the cigarettes and ensures the making of a reliable seam (where the two marginal portions of the wrapper overlie and adhere to each other) of constant width.
It is perhaps even more important to ensure that a cigarette which is to be assembled with a filter mouthpiece in a so-called tipping machine exhibit a predetermined diameter, at least at one of its ends, because this ensures the making of a reliable leakproof connection between one end of the plain cigarette and one end of the mouthpiece. The connection (which is normally established by a convoluted strip of tipping paper, such as artificial cork) is much more likely to be leakproof if the diameter of the one end of the plain cigarette matches the diameter of the adjacent end of the mouthpiece. This applies irrespective of the exact mode of making filter cigarettes. A presently preferred mode is disclosed in commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Oesterling et al. for “METHOD OF AND APPARATUS FOR MAKING FILTER CIGARETTES”. Penetration of uncontrollable quantities of air to a filter cigarette at a leaky junction between the plain cigarette and the filter mouthpiece is undesirable in spite of the fact that it is often desirable or even necessary to perforate the wrapper of a plain or filter cigarette in order to admit atmospheric air in quantities which are deemed desirable in order to exert a beneficial influence upon the nicotine and/or condensate content of tobacco smoke. Reference may be had, for example, to U.S. Pat. No. 4,121,595 granted Oct. 24, 1978 to Heitmann et al. for “APPARATUS FOR INCREASING THE PERMEABILITY OF WRAPPING MATERIAL FOR ROD-SHAPED SMOKERS' PRODUCTS”.
German patent No. 34 14 247 A1 discloses a method of and an apparatus for pneumatically ascertaining the diameters of rod-shaped articles. The patent proposes the utilization of air at constant pressure and substantially continuous monitoring of the diameter of a continuously advanced rod-shaped article. The monitoring device comprises a nozzle defining a small annular testing chamber which surrounds the continuously advancing rod-shaped article. The nozzle is operatively connected with a testing unit which is set to respond to air pressure below that required to effect a deformation of the tested article. Furthermore, the nozzle is integrated into a rod guiding arrangement in such a way that the testing chamber and the guiding arrangement flank a larger expansion chamber which communicates with the atmosphere.
An optical measuring system for the diameters of rod-shaped commodities is disclosed in German patent No. 195 23 273 A1 and in the corresponding U.S. Pat. No. 5,715,843 granted Feb. 10, 1998 to Hapke et al. for “METHOD OF AND APPARATUS FOR MEASURING THE DIAMETERS OF ROD-SHAPED ARTICLES OF THE TOBACCO PROCESSING INDUSTRY”. These patents propose to rotate a practically finished cigarette about its axis during continuous or discontinuous sidewise movement and to simultaneously direct against the cigarette a laser beam. The amounts of intercepted radiation are indicative of the diameters of the respective articles; such amounts are monitored by a camera serving to generate electric signals which are processed into second signals denoting the diameters of discrete successively tested cigarettes and/or the average diameters of series of successively tested cigarettes.
German patent No. 38 06 320 A1 proposes a method of and an apparatus for monitoring the diameter of the tubular wrapper surrounding a rod-like filler of tobacco or filter material for tobacco smoke. A first measuring unit is employed to ascertain the width of the web or strip which is to be converted into the tubular wrapper, and a second measuring unit serves to monitor the width of the seam which is established by the overlapping marginal portions of the tubular wrapper, i.e., of the converted web or strip. An evaluating arrangement is employed to process the signals denoting the width of the web and the signals denoting the width of the seam into further (difference) signals which are indicative of the diameter of the tubular wrapper, i.e., of the article consisting of a rod-like filler and the tubular wrapper around it.
German patent No. 27 17 473 A1 proposes a control arrangement for a combination of a cigarette rod maker and a filter tipping machine which latter is directly coupled to the maker and is set up to turn out filter cigarettes. The filter tipping machine includes a measuring arrangement which is designed to detect fluctuations of the diameters of filter rod sections which are to be united with plain cigarettes to form therewith filter cigarettes of desired length. The maker of plain cigarettes is provided with a control unit which can influence the diameter of the cigarette rod being produced therein. The measuring arrangement of the filter tipping machine serves to transmit to the control unit of the maker a series of reference signals or desired-value signals. Such combination of the measuring arrangement and of the control unit is intended to enable the maker to turn out plain cigarettes having diameters best suited for attachment to the filter mouthpieces which are being processed in the tipping machine.